1. Technical Field
The present invention relates to a visual field examination system that is configured using an OCT fundus device, a perimeter and a fundus image-capturing device such as a fundus camera.
2. Background Art
A perimeter having a manual or automatic measurement mode is a conventionally known device for measuring the visual field of an eye under examination. In eye diseases such as glaucoma, for example, symptoms such as constriction of visual field or scotoma are known to take place, and a perimeter is used in the diagnosis of diseases of this type.
This type of perimeter is adapted so that an illumination spot is projected as a stimulus onto a visual field dome having a hemispherical projection surface, and the projection position of the stimulus either is manually controlled or is automatically controlled in accordance with a predetermined program to record a response from the subject at respective projection positions.
If an abnormal position in the retina of an eye under examination can be identified using a two-dimensional fundus image obtained from fundus photography by a fundus camera, it would presumably be useful in diagnosis. Information obtained by comparison with not only the structure but also the function of the retina is believed to be useful in the diagnosis of glaucoma, and accordingly there have been proposed examination systems capable of combining both a fundus image and a measurement result obtained by a perimeter.
At present, there are also known devices such as an OCT (Optical Coherence Tomography) capable of measuring the layer thickness of the retina of an eye under examination. Incorporating the information (hereinafter referred to as an “OCT image”, especially for images) which relates to the three-dimensional structure of the retina obtained by this type of device would presumably make even more highly accurate diagnosis of the retina possible.
For example, Patent Document 1 discloses an ophthalmologic information processing device in which light is projected onto the fundus, and light reflected therefrom is detected to acquire a three-dimensional image indicative of the morphology of the retina of an eye under examination on the basis of a detection result using OCT technology in order to calculate the layer thickness of the retina from the three-dimensional image, the information of the retinal layer thickness being compared with the result of a visual field examination carried out in advance, thereby obtaining ophthalmologic information.
Patent Document 2 discloses an ophthalmologic examination system in which a two-dimensional fundus image is combined with a measurement result obtained by a perimeter. In the perimeter of Patent Document 2, a stimulus is presented in a position which lies on a separately captured fundus image and corresponds to a predetermined examination position within a coordinate system of a visual field dome, and the visual field is measured according to a visual response from the subject.